6-6 Sequence Graphing
8306SEQN.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:22 PM Printed: 02/19/01 1:36
PM Page 6 of 16
In a recursive sequence, the
n
th term in the sequence is
defined in relation to the previous term or the term that
precedes the previous term, represented by u(
n
N1) and
u(
n
N2). A recursive sequence may also be defined in
relation to
n
, as in u(
n
)=u(
n
N1)+
n
.
For example, in the sequence below you cannot calculate
u(5) without first calculating u(1), u(2), u(3), and u(4).
Using an initial value u(
n
Min) = 1, the sequence above
returns 1, 2, 4, 8, 16, . . .
Tip: On the TI-83, you must type each character of the terms. For
example, to enter u(
n
N1), press y [u] £ „ ¹ À ¤.
Recursive sequences require an initial value or values,
since they reference undefined terms.
• If each term in the sequence is defined in relation to the
previous term, as in u(
n
N1), you must specify an initial
value for the first term.
• If each term in the sequence is defined in relation to the
term that precedes the previous term, as in u(
n
N2), you
must specify initial values for the first two terms. Enter
the initial values as a list enclosed in braces ({ }) with
commas separating the values.
The value of the first term is 0 and the value of the second
term is 1 for the sequence u(
n
).
Recursive
Sequences